Well jointed outcrop of limestone, Cretaceous Chonta formation, some minor faults. Unini River near confluence with the Ucayali River. Same as slide 19, less instructive. Allan Craig.
Weathering by organic acids from deeply penetrating roots in syentite along road cut, Alder Gulch near Zortman Butte, Little Rocky Mountains, Montana. May, 1964.
Weathered till 8 feet thick (man at bottom, spade at top) overlain by fresh till. Contact between lowest and middle till of Wickenden, 1931b. Near Stewart Valley, Sask. Now regarded as contact between Aikins till below and Wymark till above separated by marly stratified deposits (Christiansen 1959).
Wave refraction. The manner in which waves are refracted on an irregular shoreline. It is assumed that the water is deeper off the bay off the headlands. Consider that the original wabe is divided into three equal segments A-B, B-C, and C-D. Each segment has the same potential energy. But observe that by the time the wave reaches the shore the energy of A-B and C-D has concentrated along the short shoreline of headlands A'-B' and C'-D', while the energy of B-C has been dispersed over a greater front (B'-C') around the bay. Thus there is more energy available for erosion per unit of shoreline on the headlands than there is along the bay. Leet and Judson, 1958, p. 310.